This invention relates to a balancing device for correcting imbalance in rotary elements. The invention is disclosed in the context of a wheel balancing device including correction weight for correcting imbalance in vehicle wheel-and-tire assemblies. The invention is believed to be useful in other applications as well.
Weights for application to rotary elements, such as vehicle wheel and tire assemblies to correct imbalance in such elements, are known. There are, for example, the systems illustrated and described in U.S. Pat. No. 3,960,409 and the references cited in that patent. There are also the devices described in U.S. Pat. Nos. 2,029,132; 2,640,727; 3,154,347; 3,177,039; 3,273,941; 3,748,910; 3,786,850; 3,905,648; 4,300,803; 4,379,596; 5,557,043; 5,831,152; and, 5,959,205. The disclosures of those references are hereby incorporated herein by reference. No representation is intended that a complete search has been made of the prior art or that no better art than that listed is available, and no such representation should be inferred. This listing shall not be construed to be an admission that the listed references are, or are considered to be, material to patentability.
In recent years, some vehicle wheel designs have evolved that do not permit the use of pound-on imbalance correcting weights on the outwardly facing, or xe2x80x9ccurbxe2x80x9d side of the wheel. These wheels are sometimes called xe2x80x9cflangelessxe2x80x9d or xe2x80x9csoft facexe2x80x9d wheels. Flangeless or soft face wheels generally require adhesive weights to be applied from the car side of the tire and wheel assembly to the inside diameter of the wheel to correct some portion of the imbalance in the assembly. Currently, an operator selects a specific size weight from a row of bins, removes the protective tape and applies the weight to the wheel. This process is slow and it is easy for the operator to select the wrong weight. In addition, typical currently available adhesive weights are made from pieces of lead with protective coatings to reduce the likelihood of direct worker contact with the lead. These one-piece weights are preformed to a specific wheel radius. Workers sometimes reshape the weights to the radius of a wheel for which the weights were not originally made. Otherwise, optimal adherence of the adhesive weight will not be achieved. These characteristics lead to additional work and rework at imbalance correcting stations for wheel and tire assemblies.
Another currently available system pulls extruded lead, with adhesive already applied, from a coil of extruded lead, forms the extruded lead to a particular radius, and then cuts the amount of extruded lead necessary to achieve a particular amount of imbalance correction. Weights formed using this system leave the ends of the lead weights exposed to contact with workers. This exposed lead is unacceptable to many manufacturers. Also, as noted, this system forms the extruded lead to only one radius. Again, this means that if the weight is to be applied to a wheel having another radius, the worker must reshape the weight to the desired curvature. Additionally, lead is heavy, resulting in the coils having limited capacity. This results in frequent replacement of the somewhat unwieldy coils.
The weight of the present invention is intended to address a number of these shortcomings of prior art weight application systems.
According to the invention, a weight for correcting imbalance in a rotary element includes a number of discrete weights. The number of discrete weights is selected to substantially correct the imbalance. The invention further includes a length of double sided tape sufficient for the number of discrete weights to be adhered to the length of double sided tape. A removable film protects the side of the tape opposite the side to which the discrete weights are adhered. The film reduces the likelihood of contamination until the film is removed to expose the side of the tape opposite the side to which the discrete weights are adhered, permitting the weight to be applied to the rotary element.
Illustratively according to the invention, the discrete weights are substantially uniform in weight.
Further illustratively according to the invention, the length of double sided tape is elastic, permitting it to stretch slightly during application to the rotary element.
Additionally illustratively according to the invention, the discrete weights are coated with a coating which reduces the likelihood of contact by someone handling the weight with the discrete weights.
Illustratively according to the invention, each of the discrete weights includes an external surface, the entirety of which is coated with the coating.
Illustratively according to the invention, the discrete weights are substantially uniform in configuration.
Further illustratively according to the invention, the discrete weights are generally right rectangular prism shaped.
Additionally illustratively according to the invention, the discrete weights have somewhat rounded corners between at least two adjacent sides providing a detectable boundary between adjacent discrete weights to aid in determining the number of discrete weights in the weight.
Illustratively according to the invention, each of the discrete weights includes an upper surface spaced apart from the double sided tape, and a lower surface that is coupled to the double sided tape. A first side and a second side connect the upper surface and the lower surface. The lower surface of each of the discrete weights is planar from its junction with the first side to its junction with the second side.